1. Field of Invention
This invention relates to an improved heat sink for cooling modules containing semiconductor chips. More particularly, a heat sink having a peak near its center for enhancing cooling efficiency is disclosed.
2. Background Information
As the density of very large scale integrated (VLSI) circuits continues to increase, the amount of heat generated also increases and becomes more of a problem. In air cooled semiconductor modules, cooling is facilitated by the use of fins of heat conducting material to increase the surface area for radiating heat to the air. Examples of such structures can be found in the IBM Technical Disclosure Bulletin, "Cooling Fin Structure" by J. L. Horvath, Vol. 23, No. 2, July 1980, page 603.
This structure consists of a network of vertical, serpentine fins mounted on a base element, typically a cover for a semiconductor package. Since the base element is flat, this cooling structure is effective in both transverse and impingement air flow. However, this design is inefficient during impingement air flow since the air parts as it hits the surface, thereby creating a dead space near the top surface of the heat sink (FIG. 1). The presence of this dead space limits the cooling efficiency of the heat sink.
While in the past, this limitation has not been a problem, this is no longer the case. Circuit densities have increased so greatly that any limitation in heat transfer can no longer be tolerated. Accordingly, it is desirable to have a heat sink suitable for cooling a semiconductor module with a vertical impingement air flow that maximizes the cooling efficiency by eliminating the dead space.